High Spatial Resolution Simulation of Sunshine Duration over the Complex Terrain of Ghana

Area of Science:

• Remote Sensing
• Environmental Modeling
• Solar Radiation

Background:

• Accurate estimation of sunshine duration and percentage is crucial for various applications.
• Existing models often struggle to integrate complex terrain and atmospheric influences effectively.

Purpose of the Study:

• To develop and validate a novel remote sensing model for estimating spatio-temporal sunshine percentage (SSP) and sunshine duration (SD).
• To assess the model's performance against classical interpolation techniques and ground-based observations.

Main Methods:

• A 1x1 km spatial resolution remote sensing model was developed.
• Incorporated a digital elevation model (DEM) for topography and moderate-resolution imaging spectroradiometer (MODIS) cloud products for atmospheric factors.
• Validated against in situ observation data and compared with kriging and inverse distance weighting (IDW) methods.

Main Results:

• The model successfully estimated annual and monthly average daily SSP and SD.
• Modelled sunshine duration (SD) showed good agreement with ground-based observations.
• The proposed model outperformed kriging and IDW methods in terms of MAE, MRE, and RMSE.

Conclusions:

• The developed model reliably quantifies the impact of terrain and cloud cover on sunshine duration estimation.
• The model is expected to perform well in Ghana and similar environmental conditions.
• This approach offers a significant improvement for spatio-temporal sunshine estimation using remote sensing data.